SAN FRANCISCO -- A top Pacific Gas and Electric Co. gas official assured state regulators Monday that despite some confusion in critical testing at a natural-gas installation in the Mojave Desert, the site is in good working condition and can safely be restored to full operation as colder weather nears for Northern and Central California.

PG&E wants to be free of the 20 percent pressure cut that state regulators imposed in February at the Topock compressor station near Needles (San Bernardino County) because of an overpressurization incident. Continued restrictions could keep the company from meeting peak winter demand, PG&E says.

PG&E went before the California Public Utilities Commission on Monday seeking authorization to return to full pressure at the station, which receives natural gas from Arizona and funnels it into two major pipelines that terminate in Milpitas. The commission is expected to issue a tentative decision in about two weeks.

Engineers with the commission had cited "deficiencies" in the method that a PG&E contractor used to test the station over the summer to see whether it had been damaged by the overpressurization. The contractor used a lower-pressure water test than the state expected, the commission engineers said, and the equipment used was not calibrated to PG&E's standards.

Regulators ordered that future testing comply with all rules and standards, but found that the testing used at Topock was "adequate" to return the station to full pressure.

Regulators want a double test, known as a "spike test" - involving a brief spike in pressure during an eight-hour procedure - and not the single-pressure test over an eight-hour period that PG&E's contractor used at Topock.

At a hearing in San Francisco before a utilities commission administrative law judge, which two commissioners attended, PG&E's vice president of gas standards and policy, Jane Yura, promised that the company would not depart from the spike-testing regimen in the future without state approval.

Yura acknowledged a "lack of clarity" and "confusion" within PG&E's own standards governing what kind of measuring equipment should be used in spike tests and how it should be calibrated.

Commissioner Mike Florio asked Yura about her confidence level of the Topock station's pipes in light of the testing.

"I'm highly confident, because we tested them to a very high pressure and we will operate them at a very low percentage" of the maximum allowable level, Yura said.

After the hearing, Florio said the testing appeared to have shown that the station was safe and that any problems in the process were simply "glitches."

"I'm much more confident than I was coming into this hearing," Florio said.

"I would have much preferred this first one come in squeaky clean with no wrinkles," he said. "But at this point, subject to further follow-up, I'm reasonably satisfied that these were fairly minor things, that these lines were tested at far above the pressure that they would be expected to encounter in normal operation."

The Topock station was the first of about a dozen natural gas installations and major pipelines for which PG&E is seeking to restore full pressure following state-mandated pressure testing. The state ordered pressure cuts and the testing in the wake of last September's explosion of a PG&E gas transmission line in San Bruno, where the company had never performed pressure tests because of inaccurate records.

"This is a critical facility," Florio said. "This is the gateway of gas from the U.S. Southwest to the PG&E system, and if it were not safe to operate, we would have serious problems.

"Subject to the internal follow-up that we will be doing," Florio said, "I'm cautiously optimistic. "

Complete coverage: To read "Report to America on Pipeline Safety," or to see Chronicle reports since the San Bruno pipeline blast, video of the disaster, and company and government documents about PG&E's actions, go to www.sfgate.com/san-bruno-fire.